title: Epidermal stratification reduces the effects of UVB (but not UVA) on keratinocyte cytokine production and cytotoxicity.
abstract: Ultraviolet (UV) radiation induces cytokine release from cultured keratinocytes as well as from epidermis in vivo. The purpose of this study was to determine whether differentiation of cultured keratinocytes into stratified epithelium decreases the effects of UVA and UVB radiation on cytokine release. Interleukin-1 (IL-1) alpha, IL-1 beta and tumor necrosis factor (TNF)-alpha release from human keratinocytes and reconstituted human epidermis was measured after exposure to UVA or UVB radiation. Release of IL-1 alpha, IL-1 beta, and TNF-alpha was induced by both UVA and UVB radiation from both keratinocytes and reconstituted epidermis. Release of these cytokines was correlated with cytotoxicity. Keratinocyte cultures were far more sensitive to UVB radiation than reconstituted epidermis, in terms of both cytotoxicity and cytokine release. In contrast, epidermal stratification/differentiation had much less effect on the sensitivity to UVA radiation. We conclude that epidermal stratification and the formation of a stratum corneum provide protection against UVB radiation but have limited barrier effect against UVA radiation.
authors.affiliation: Department of Dermatology and Pathology, Wake Forest University, Bowman Gray School of Medicine, Winston Salem, NC 27157-1071, USA.
authors.forename: E
authors.initials: E
authors.lastname: Corsini
authors.forename: N
authors.initials: N
authors.lastname: Sangha
authors.forename: S R
authors.initials: SR
authors.lastname: Feldman
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D002454:Cell Differentiation; D002470:Cell Survival / Q000528:radiation effects; D002478:Cells, Cultured; D046508:Culture Techniques; D003602:Cytotoxicity, Immunologic / Q000187:drug effects / Q000528:radiation effects*; D004797:Enzyme-Linked Immunosorbent Assay; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects / Q000276:immunology / Q000528:radiation effects*; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology; D007375:Interleukin-1 / Q000096:biosynthesis / Q000378:metabolism / Q000528:radiation effects*; D015603:Keratinocytes / Q000187:drug effects / Q000201:enzymology / Q000276:immunology / Q000528:radiation effects*; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D011829:Radiation Dosage; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000145:classification*
chemical_list: D000893:Anti-Inflammatory Agents; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D007770:L-Lactate Dehydrogenase; D006854:Hydrocortisone